Most ferries were unable to depart on schedule from Piraeus and other Athens ports / AFP

Two Vietnamese tourists died at sea in Greece on Friday, the coastguard said, as gale-force winds confined many ferries to port, disrupting tens of thousands of summer travellers, and sparked wildfires.

A coastguard spokeswoman said a man and woman had died at the Sarakiniko beach on the tourist island of Milos in the Cyclades, as firefighters battled blazes near Athens and on the island of Cephalonia.  

"The man and woman were found unconscious in the sea and were taken to the local health centre," the spokeswoman said.

"They were Vietnamese tourists on a cruise ship group. The woman fell in the water and the man apparently tried to save her," she said.

The civil protection ministry had said wind gusts would reach 88 kilometres (54 miles) an hour, especially in the southern Aegean and the Sea of Crete.

More than 200 firefighters backed by 11 water bombers and seven helicopters were battling a fire in Keratea, southeast of Athens, Costas Tsigkas, head of the association of Greek firefighter officers, told ERT state television.

"It's a difficult fire... (owing) to wind gusts," he said, adding that several communities had been evacuated.

"The fire front is seven kilometres, homes are under threat," a local mayor, Dimitris Loukas, told ERT, adding that the wind was complicating efforts to douse the blaze from the air.

The Cephalonia fire was earlier placed under control, local officials said.

National weather service EMY said the winds would weaken after midnight.

- 'Left stranded' -

The coastguard said most ferries were unable to depart on schedule from Piraeus and other Athens ports, especially to the Cyclades or Dodecanese islands. Several services were cancelled and others postponed.

At Piraeus, hundreds of people crowded outside a ferry that was bound for the Cycladic islands of Paros and Naxos, waiting for news on a possible departure. 

Nearby, stranded travellers surrounded by rucksacks and suitcases formed a huge queue outside a ticket office and made desperate phone calls hoping to make rearrangements to save their journeys.

"There's huge lines, huge commotion, everyone's waiting in the sun and it's a very tough time," said Philip Elias, an American tourist.

Sergi Gros, a 51-year-old civil servant from Spain, said he was scrambling to find last-minute accommodation in Athens for two nights, having already lost his booking on the island of Astypalea.

"We arrived at 6:45 in the morning and they told us the ferry was cancelled," Gros told AFP, saying there was a "total lack of information".

"I don't think (the hotel) can be refunded because it's not their fault. It's a great shame because we booked with a big (ferry) company, and there are people who reserve months in advance... they left us stranded," he said.

Maritime connections with the Saronic islands near Athens including Aegina, Hydra, Poros and Spetses and the Ionian Sea were unaffected, the coastguard said.

Strong winds are common in Greece at this time of year, and firefighters have already faced several major blazes this summer, including on the islands of Evia and Chios and in the western Peloponnese. 

imm-jph-hec/js